1. Field of the Invention
The present invention relates to a handheld electronic device. More particularly, the present invention relates to a handheld electronic device and a method for switching a user interface thereof.
2. Description of Related Art
To cope with a high demanding efficiencies and multifunctional devices required by modern human beings, more and more functions used to be only implemented in a personal computer are now gradually integrated into a cell phone. The cell phone of a new generation not only has a function of making phone calls, but also has functions such as playing multimedia file, surfing internet, tranceiving email, managing personal data and schedule, or processing simple document etc. However, as the functions are increasingly powerful, required key types and key number are increased accordingly. Now, considering both screen space and keyboard space, sliding design of the cell phone has gradually become a general trend recently.
FIG. 1A is a schematic diagram illustrating an appearance of a conventional slide cell phone. Before a cover of the cell phone is slid out, a keyboard thereof is hidden behind a body of the cell phone. As shown in FIG. 1B, when the cover is slid away, the keyboard is then slid out from a side of the cell phone for inputting commands. According to a deploying direction of keyboard keys, when the keyboard is slid out from the side of the cell phone, the cell phone is generally rotated for 90 degrees for operation. For operation convenience of the cell phone, direction and content of displayed images are generally varied according to a present state of the cell phone during operation of internal software of the cell phone. Referring to FIGS. 1A and 1B, by comparing images displayed on a screen 110 and a screen 120, it is discovered that when the keyboard is slid out and the cell phone is rotated at 90 degrees, display direction of the image is then changed from a portrait mode shown as FIG. 1A to a landscape mode shown as FIG. 1B. Therefore, the user may refer to the image displayed in the landscape mode while operating the keyboard, by which a problem of inconsistency between the displayed image and the keyboard is avoided, such that a desired option displayed thereon may be conveniently selected.
However, regardless of the image being displayed in the portrait mode or the landscape mode, the user has to click and select repeatedly for obtaining a desired function menu, and then a desired application program to be executed is selected from the function menu. Therefore, such operation method is inconvenient for the user. For example, when a cell phone with a built-in windows operating system is used for sending an email, a keyboard thereof is first slid out for inputting characters, and then a position of email application program is gradually selected from a “start” menu of a standby mode of the cell phone, so as to execute the application program. Therefore, such method leads to a waste of a lot of time, and the user may tend to have a negative utilization sense of the cell phone.